Disposable absorbent articles have been commercially available for many years and have met with great success world wide. For example, continuing improvements to catamenial devices have freed women from much of the inconvenience of their monthly menstrual period. However, further improvements are still needed.
One class of catamenial device, interlabial pads, has the potential to provide even greater freedom from inconvenience because of the discretion provided by their small size and reduced risk of leakage. Numerous attempts have been made in the past to produce an interlabial pad which would combine the best features of tampons and sanitary napkins while avoiding at least some of the disadvantages associated with each of these types of devices. Examples of such devices are described in U.S. Pat. No. 2,917,049 issued to Delaney on Dec. 15, 1959, U.S. Pat. No. 3,420,235 issued to Harmon on Jan. 7, 1969, U.S. Pat. No. 4,595,392 issued to Johnson, et al. on Jun. 17, 1986, and U.S. Pat. Nos. 5,074,855 and 5,336,208 issued to Rosenbluth, et al. on Dec. 24, 1991 and Aug. 9, 1994 respectively, and U.S. Pat. No. 5,484,429 issued to Vukos, et al. on Jan. 16, 1996. A commercially available interlabial device is Fresh 'n Fit.RTM. Padette which is marketed by ATHENA Medical Corp. of Portland, Oreg. and described in U.S. Pat. Nos. 3,983,873 and 4,175,561 issued to Hirschman on Oct. 5, 1976 and Nov. 27, 1979 respectively. While the Fresh 'n Fit.RTM. Padette has enjoyed some commercial success, such interlabial devices lack a barrier to prevent absorbed bodily fluids from passing through the device and staining a wearer's undergarments or other clothing.
In the past a number of attempts have been made to provide flushable absorbent articles. British Patent No. 282,447 attempts a partial solution by providing a core said to be flushable and a repellent treated barrier which is separated from the core and needs to be disposed of by other means. U.S. Pat. No. 3,078,849, issued to Morse on Feb. 26, 1962, describes a sanitary napkin incorporating a fluid sensitive, temporary barrier within the absorbent core for spreading bodily fluids but makes no provision for a water sensitive outer covering. U.S. Pat. No. 3,561,447, issued to Alexander on Mar. 13, 1969, describes a sanitary napkin having a nonwoven fabric covering wherein the nonwoven fabric comprises textile length fibers and the binder for the nonwoven is a combination of a soft acrylic binder and polyvinyl alcohol. This combination is said to have sufficient strength when damp to serve as an outer covering while still dispersing in water when exposed to mild agitation. While such a structure may have limited wet strength, it is unlikely that it will have sufficient barrier properties to be a satisfactory backsheet for a modern sanitary napkin. U.S. Pat. No. 3,665,923, issued to Champaigne, Jr. on May 30, 1972, describes a sanitary napkin with an wrapper comprising a nonwoven fiber web that is bonded by a water dispersible adhesive such as poly (vinyl alcohol). A preferred embodiment also comprises a baffle member of a thin impervious plastic film interposed between the absorbent pad and the wrapper. This structure solves the problem of providing barrier properties by providing a non dispersible member with the requisite barrier properties. Repeated flushing of such structures poses the risk of clogging sewer pipes because the baffle member will not disperse into small particles in a toilet. U.S. Pat. No. 5,300,358, issued to Evers on Apr. 5, 1994 describes absorbent structures wherein the backsheet comprises two sheets of poly (vinyl alcohol) film with a highly absorbent paper structure therebetween. All surfaces that may be exposed to aqueous fluids are treated with a water repellent material, such as a fluorocarbon. The absorbent structure is also provided with a tear strip or string which, when pulled at disposal, is said to expose the highly absorbent paper structure to water which then wicks the water to the non repellent treated surfaces so they can dissolve. The requirement of a tear strip is an obvious inconvenience.
Thus, it is an object of the present invention to provide an interlabial absorbent structure with performance properties (such as wearer comfort, leakage resistance, and the like) equaling or exceeding those of contemporary interlabial devices. It a further object of the present invention to provide interlabial absorbent structures that provide improved convenience and discretion when the used interlabial absorbent structure is disposed of. It is still a further object of the present invention to provide an interlabial absorbent structure that may be disposed of by flushing the article down a conventional toilet wherein the interlabial absorbent structure readily disperses into portions sufficiently small so as not to clog plumbing when the used interlabial absorbent structure is flushed.